I loved watching Ducktales as a kid and have the recent DVD releases. I will admit I only read a few of the comics, but might need to see if I can find some of the reprints someday. So I don't think the show was bad by any means, just a bit different. As for Donald's absence in Ducktales, the reason he isn't in the show was that he was the most famous character in the series, and most people weren't as familiar with the others people in the series, and the thought that if he was in it much at all, people would expect him to be the hero or expect a purely slapstick comedy, like his shorts. So they decided to write him out, and replaced the role he played with Lauchpad. But IIRC, some episodes are taken directly out of the comics. But its like that with any comic adapted for a TV show or movie. You can't take it as is in the comics. You have to make some changes for the TV/movie screen.
To answer your question on why Donald got them, I've finally thought of the answer. Donald is the only one who could understand and talk to Hewey, Dewey, and Louie. So he got them. Nobody else talks like they do.